use strict;
use Benchmark qw(cmpthese);

# A big, sorted list (475254 elements)
my @list = ('a'..'zzzz');
##Put the list into a string

my $string = join(/ /, @list);

$string .= "\n";

cmpthese(0, {
       # Looking for a random item in @list with grep
        index => sub {
                # A random element in the list
                my $pattern = 'fqsu  fqsv  fqsw  fqsx  fqsy';
                my $result = index($string, $pattern);

        },
        # Looking for a random item in @list linearly (with foreach)
        regex  => sub {
                my $pattern = 'fqsu  fqsv  fqsw  fqsx  fqsy';
                $string =~ /$pattern/;
        },
    }

);
[download]

mrguy123,

As requested ( I typed this in from the code ):

sub index
{  if ( index('yabba dabba doo','abba' ) >= 0 ) { }
}

sub regex
{   $_ = 'yabba dabba doo';
    if ( /abba/ ) { }
}

cmpthese ( 500_000, 
   {  regex => sub { &regex },
      index => sub { &index },
   },
 );
[download]

I have found 'index' usually faster than 'regex' in this type of situation, but 'regex' has more power when needed.

Regards...Ed

"Well done is better than well said." - Benjamin Franklin